“There’s still a lot that’s unknown. We actually can’t do the studies to see if it’s a good treatment or a bad treatment [for certain conditions],” Senator Paul said, explaining that making marijuana a Schedule II substance would ensure easier access for scientists. “With Schedule I, it’s virtually impossible. It’s just too hard.”

Gillibrand agreed, pointing to the harsh prohibitions on cannabis as compared to relatively lax regulations on opiate derivatives like methadone and OxyContin. “Going to smoke in an opium den is not legal, but the drug can be analyzed…and prescribed as codeine and other drugs people have access to when they have pain,” she said.

According to sources who spoke with the Washington Post, the bill will also “reclassify the drug in the eyes of the Drug Enforcement Administration.”

The number of states that have legalized medical marijuana has grown to twenty-three, along with Washington, D.C., and twelve have legalized cannabidiol, a hemp oil that offers medical benefits without the high. However, federal laws against the plant can leave growers, dispensary operators, and even doctors in dicey legal territory.

In 2014, the Boston Globe reported on DEA officials who targeted pro-medical-marijuana physicians in Massachusetts with the ultimatum to “sever all ties to marijuana companies, or relinquish federal licenses to prescribe certain medications.” And later that year, the DEA raided two Los Angeles outlets of a dispensary called the Farmacy. “We are completely in the dark as to why this happened,” a Farmacy manager told the Huffington Post. “We are completely 100 percent state-compliant and we pay our taxes.”

Michael Collins, of the pro-legalization Drug Policy Alliance, says the new measure will clear up those distinctions between state and federal law by repealing national prohibition of the drug for medical purposes. “Right now, growers and dispensary owners are open to prosecution,” he says. “This bill will take a step in ending that criminalization.”

The trio of Gillibrand, Booker, and Paul seems unlikely, but the Democratic East Coasters have worked with the gun-loving Kentucky libertarian before. Booker and Paul sponsored a previous amendment to a Senate jobs bill — a measure to prevent the DEA from arresting patients or providers in states where marijuana was legal.

And in 2013, Paul co-sponsored Gillibrand’s “Military Justice Improvement Act,” which would have allowed sexual assault in the military to be prosecuted by a federal civilian court.

For advocates like Collins, the bill’s unique combination of supporters — legislators from opposite ends of the political spectrum — offers hope that legal access to the drug is not too far away.

“These senators have a national profile,” he says. “These guys are household names…there’s a real sense that this is inevitable now: We need to end federal prohibition of marijuana and let states make their own decisions.”

You can watch the full press conference here:

In the video, you’ll see T.J. Thompson, an Army veteran from Virginia who takes medical marijuana for clinical depression, applauding the bill. He called it a “monumental step forward” on what he considers to be a First Amendment issue.

“Veterans are censored from speaking openly to their doctors about their treatment options,” said Thompson, a spokesman for Veterans for Medical Cannabis Access who uses medical marijuana to combat “suicidal and homicidal thoughts.”

Currently, doctors in Veterans Affairs hospitals are not allowed to prescribe medical marijuana even in states where the drug is legal. “Veterans have volunteered to protect our rights and freedoms that made this country great,” he said. Now, he added, it was time for lawmakers to “respect our rights to heal.”